NORWICH, England (UPI) — A British scientist says he’s developed a mathematical model that suggests the odds of finding life on another Earth-like planet are very low.

University of East Anglia Professor Andrew Watson said an evolutionary limit is the habitability of Earth-like planets that will end as their star brightens.

Scientists say the future life span of Earth will be about another 1 billion years — a short time compared with the 4 billion years since life first appeared on the planet, he said.

“At present, Earth is the only example we have of a planet with life,” said Watson. “If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect evolution from simple to complex intelligent life was quite likely to occur

“By contrast, we now believe we evolved late in the habitable period and this suggests our evolution is rather unlikely,” he added. “In fact, the timing of events is consistent with it being very rare indeed.”

The finding, reported in the journal Astrobiology, suggests the chance of intelligent life emerging is less than 0.01 percent over 4 billion years.